METHOD OF CALCIUM SULFATE PRODUCING Russian patent published in 1994 - IPC

FIELD: chemical technology. SUBSTANCE: acid sewage in manufacture of activated bentonite containing H₂SO₄, Al₂(SO₄)₃, MgSO₄, H₂(SO₄)₃, CaSO₄ are neutralized with natural lean gypsum rock of the following composition, wt. -% : CaSO₄ 10-49; CaCO₃ 21-89.9; clay 0.1-30 at the mole ratio CaCO₃/H₂SO₄ = 1.81-2.8. After that suspension is filtered, and precipitated is dried at 150-180 C for 30-60 min. Prepared product shows binding properties and can be used in building material production. Method is used for dispersed gypsum product producing. EFFECT: improved method of producing. 2 cl, 3 dwg, 2 tbl